Hard jaws from Dillon Mfg. Inc. feature diamond-shaped serrations for increased pull-down effect, which helps reduce part slippage and pushback from using a bar feeder. The serrations on the gripping surfaces also are suitable for cast parts, scaly parts, or parts with imperfections.

The hard jaws are manufactured of 1018 or 8620 steel, which is then case-hardened and coated with black oxide for corrosion resistance. They are available in different mounting configurations, including serrated, T&G, Acme, and square serrated key types, to fit all brands of chucks.